100 research outputs found
Effectiveness of woodland birds as taxonomic surrogates in conservation planning for biodiversity on farms
Woodland birds are a commonly used taxonomic surrogate for other species groups in agricultural landscapes as they are relatively diverse, easily-studied, and charismatic. Yet, other taxa can respond to native vegetation on farms differently to woodland birds, challenging the present focus on birds in agri-environmental schemes. We aimed to assess the effectiveness of woodland birds as taxonomic surrogates for biodiversity in conservation planning on farms, in comparison with reptiles and arboreal marsupials. We used a complementarity-based approach to select patches of remnant and restored vegetation that supported a priori representation targets of species occurrences. We found that the spatial locations of vegetation patches selected to meet representation targets for woodland birds were 24%–69% different from the locations of patches selected for other taxa. The vegetation patches selected to meet representation targets for woodland birds failed to incidentally meet representation targets for other taxa, although targets for a subset of threatened woodland birds were exceeded. Conservation planning for woodland birds, however, led to higher incidental representation of the other taxa, compared with conservation planning for reptiles and arboreal marsupials. This indicates that woodland birds are a more effective taxonomic surrogate for biodiversity on farms compared to reptiles and arboreal marsupials. If the conservation goal is to conserve a broad array of biodiversity on farms, then the focus on woodland birds in agri-environmental schemes is justified. However, if the conservation of particular species or taxonomic groups is a priority, then conservation plans explicitly targeting these species or groups are required.We thank the Australian Research Council (ARC Linkage Project LP100100467) and the Murray and Riverina Local Land Services for funding for this project
Long-term bird colonization and turnover in restored woodlands
The long-term effectiveness of restored areas for biodiversity is poorly known for the majority of restored ecosystems worldwide. We quantified temporal changes in bird occurrence in restoration plantings of different ages and geometries, and compared observed patterns with a reference dataset from woodland remnants on the same farms as our plantings. Over time, bird species richness remained unchanged in spring but exhibited modest increases in winter. We found that wider plantings supported significantly greater bird species richness in spring and winter than narrow plantings. There was no evidence of a significant interaction between planting width and time. We recorded major temporal changes in the occurrence of a range of individual species that indicated a clear turnover of species as plantings matured. Our results further revealed marked differences in individual species occurrence between plantings and woodland remnants. Life-history attributes associated with temporal changes in the bird assemblage were most apparent in winter survey data, and included diet, foraging and nesting patterns, movement behaviour (e.g. migratory vs. dispersive), and body size. Differences in bird assemblages between plantings of different ages suggest that it is important that farms support a range of age classes of planted woodland, if the aim is to maximize the number of native bird species in restored areas. Our data also suggest that changes in the bird species occupying plantings of different ages can be anticipated in a broadly predictable way based on planting geometry (especially width) and key life-history attributes, particularly movement patterns and habitat and diet specialisation. © 2016, Springer Science+Business Media Dordrecht. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record*
Cross-taxonomic surrogates for biodiversity conservation in human-modified landscapes – A multi-taxa approach
Cross-taxonomic surrogates are often used in conservation planning because inventorying large suites of taxa is either not feasible or too costly. However, cross-taxonomic surrogates are seldom tested rigorously using both correlational and representation-based approaches at the spatial scales at which conservation management occurs. Here, we evaluated the effectiveness of five ecologically contrasting taxa (birds, herpetofauna, wild bees, beetles, trees) as cross-taxonomic surrogates in native woodland patches within a heavily modified, farming and plantation-dominated landscape. We first compared species richness and compositional heterogeneity across taxa before testing for cross-taxonomic congruence using a correlative approach. We then quantified how well each taxon incidentally represented other taxa in their best patch sets, and the costs of doing so using a complementarity-based approach. We found significant pairwise associations between some taxa (birds, bees), but no single taxon was strongly correlated with all other taxa. Woodland patch sets prioritised for beetles represented other taxa best, followed by birds, but were the costliest and required the largest amount of woodland. This contrasted with patch sets prioritised for wild bees or herpetofauna, which achieved higher representation of other taxa at lower costs. Our study highlighted the influence of taxon-specific patterns of diversity and heterogeneity on how remnant vegetation patches should be prioritised for conservation, a consideration not immediately obvious in correlative analyses of surrogacy. Second, taxa that are not the most speciose (e.g. wild bees) can be efficient surrogates, achieving higher incidental representation for other taxa at lower costs. Thus, while species-rich taxa are ideal as surrogates for prioritising conservation, conservation planners should not overlook the potential of less speciose taxa such as bees, while considering the cost-effectiveness of surveying multiple different taxa. © 2018. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton" is provided in this record*
Beyond pattern to process: Current themes and future directions for the conservation of woodland birds through restoration plantings
Habitat loss due to land conversion for agriculture is a leading cause of global biodiversity loss and altered ecosystem processes. Restoration plantings are an increasingly common strategy to address habitat loss in fragmented agricultural landscapes. However, the capacity of restoration plantings to support reproducing populations of native plants and animals is rarely measured or monitored. This review focuses on avifaunal response to revegetation in Australian temperate woodlands – one of the world’s most heavily altered biomes. Woodland birds are a species assemblage of conservation concern, but only limited research to date has gone beyond pattern data and occupancy trends to examine whether they persist and breed in restoration plantings. Moreover, habitat quality and resource availability, including food, nesting sites, and adequate protection from predation, remain largely unquantified. Several studies have found that some bird species, including species of conservation concern, will preferentially occupy restoration plantings relative to remnant woodland patches. However, detailed empirical research to verify long-term population growth, colonisation and extinction dynamics is lacking. If restoration plantings are preferentially occupied but fail to provide sufficient quality habitat for woodland birds to form breeding populations, they may act as ecological traps, exacerbating population declines. Monitoring breeding success and site fidelity are under-utilised pathways to understanding which, if any, bird species are being supported by restoration plantings in the long term. There has been limited research on these topics internationally, and almost none in Australian temperate woodland systems. Key knowledge gaps centre on provision of food resources, formation of optimal foraging patterns, nest predation levels and the prevalence of primary predators, the role of brood parasitism, and the effects of patch size and isolation on resource availability and population dynamics in a restoration context. To ensure that future restoration plantings benefit woodland birds and are cost-effective as conservation strategies, the knowledge gaps identified by this review should be investigated as priorities in future research.NESP Threatened Species Recovery Hub, NSW Environmental Trust, Ian Potter Foundation, Vincent Fairfax Family Foundation, Riverina Local Land Services and Murray Local Land Service
Vegetation structure moderates the effect of fire on bird assemblages in a heterogeneous landscape
Ecological theory predicting the impact of fire on ecological communities is typically focused on post-disturbance recovery processes or on disturbance-diversity dynamics. Yet the established relationship between vegetation structure and animal diversit
Large trees are keystone structures in urban parks
Large trees are considered keystone structures in agricultural and forestry production landscapes, but research demonstrating this in urban landscapes is urgently needed. If large trees are keystone structures in urban parks, it is imperative that this is recognized in policy to ensure their ongoing existence. We studied the role of large native trees for birds in urban parks in Canberra, Australia. We found that (1) large trees had a consistent, strong, and positive relationship with five measures of bird diversity, and (2) as trees became larger in size, their positive effect on bird diversity increased. Large urban trees are therefore keystone structures that provide crucial habitat resources for wildlife. Hence, it is vital that they are managed appropriately. With evidence-based tree preservation policies that recognize biodiversity values, and proactive planning for future large trees, the protection and perpetuation of these important keystone structures can be achieved
Using trait-based filtering as a predictive framework for conservation: A case study of bats on farms in southeastern Australia
1.With world-wide changes in human land use, an important challenge for conservation biologists is to develop frameworks to predict how species will respond to landscape change. Environmental filtering, where different environments favour different species' traits, has the potential to be a useful predictive framework. Therefore, it is important to advance our understanding of how species with different traits respond to environmental variables. 2.We investigated the distribution of microbats in a 1000000ha agricultural region in southeastern Australia, with specific emphasis on the effects of tree density on bat species characterized by different sizes, wing shapes and echolocation frequencies. The study area is substantially cleared, and trees are continuing to decline because grazing inhibits tree regeneration. We monitored bat activity acoustically at 80 sites spanning a wide range of tree densities. We used regression modelling to quantify the response of bats to tree density and other ecological covariates, and RLQ analysis to assess how different traits correlated with various environmental gradients. 3.Total bat activity and species richness peaked at intermediate tree densities. Species composition was explained by tree density and the traits of individual species. Sites with low tree cover were dominated by large, fast-flying species, whereas sites with dense tree cover were dominated by smaller, highly manoeuvrable species. These findings are consistent with recent findings from other locations around the world. 4.Synthesis and applications. Trait-based predictive frameworks enable landscape managers to assess how different management strategies and landscape modifications are likely to affect different species. Here, we propose a framework to derive general predictions of how bats respond to landscape modification, based on tree density and species traits. We apply this framework to a current conservation issue of tree decline in our study area and derive management priorities including: (i) maintaining a range of tree densities throughout the region; (ii) ensuring the persistence of locations with intermediate tree densities; and (iii) using environmentally sensitive grazing practices, for example, by incorporating long rest periods. Trait-based predictive frameworks enable landscape managers to assess how different management strategies and landscape modifications are likely to affect different species. Here, we propose a framework to derive general predictions of how bats respond to landscape modification, based on tree density and species traits. We apply this framework to a current conservation issue of tree decline in our study area and derive management priorities including: (i) maintaining a range of tree densities throughout the region; (ii) ensuring the persistence of locations with intermediate tree densities; and (iii) using environmentally sensitive grazing practices, for example, by incorporating long rest periods
Avian functional responses to landscape recovery
Restoring native vegetation in agricultural landscapes can reverse biodiversity declines via species gains. Depending on whether the traits of colonizers are complementary or redundant to the assemblage, species gains can increase the efficiency or stability of ecological functions, yet detecting these processes is not straightforward.We propose a new conceptual model to identify potential changes to complementarity and redundancy in response to landscape change via relative changes in taxonomic and functional richness.We applied our model to a 14-year study of birds across an extensive agricultural region. We found compelling evidence that high levels of landscape-scale tree cover and patch-scale restoration were significant determinants of functional change in the overall bird assemblage. This was true for every one of the six traits investigated individually, indicating increased trait-specific functional complementarity and redundancy in the assemblage. Applying our conceptual model to species diversity data provided new insights into how the return of vertebrates to restored landscapes may affect ecological function. © 2019 The Author(s)
Evaluating complementary networks of restoration plantings for landscape-scale occurrence of temporally dynamic species
Multibillion dollar investments in land restoration make it critical that conservation goals are achieved cost-effectively. Approaches developed for systematic conservation planning offer opportunities to evaluate landscape-scale, temporally dynamic biodiversity outcomes from restoration and improve on traditional approaches that focus on the most species-rich plantings. We investigated whether it is possible to apply a complementarity-based approach to evaluate the extent to which an existing network of restoration plantings meets representation targets. Using a case study of woodland birds of conservation concern in southeastern Australia, we compared complementarity-based selections of plantings based on temporally dynamic species occurrences with selections based on static species occurrences and selections based on ranking plantings by species richness. The dynamic complementarity approach, which incorporated species occurrences over 5 years, resulted in higher species occurrences and proportion of targets met compared with the static complementarity approach, in which species occurrences were taken at a single point in time. For equivalent cost, the dynamic complementarity approach also always resulted in higher average minimum percent occurrence of species maintained through time and a higher proportion of the bird community meeting representation targets compared with the species-richness approach. Plantings selected under the complementarity approaches represented the full range of planting attributes, whereas those selected under the species-richness approach were larger in size. Our results suggest that future restoration policy should not attempt to achieve all conservation goals within individual plantings, but should instead capitalize on restoration opportunities as they arise to achieve collective value of multiple plantings across the landscape. Networks of restoration plantings with complementary attributes of age, size, vegetation structure, and landscape context lead to considerably better outcomes than conventional restoration objectives of site-scale species richness and are crucial for allocating restoration investment wisely to reach desired conservation goals.We thank the Australian Research Council, the Murrayand Riverina Local Land Services, and the Caring for OurCountry Program for funding for this project
Avifauna and urban encroachment in time and space
AIM: Urban expansion significantly alters fringe environments often with unde-sirable impacts on biodiversity. Consequently, there is a need to define clearconservation objectives for areas subject to urban encroachment. Urban fringe development is a highly dynamic process, both spatially and temporally, but few studies are equipped to examine its temporal effects on biota. We aimed to explore the impacts of urban encroachment on avifauna through space and time.LOCATION: The Australian Capital Territory, Australia. METHODS: We used records from an extensive 14-year monitoring programme undertaken in temperate woodland. We fitted hierarchical generalized linear models to assess individual species responses to the distance from monitoring sites to the urban boundary, and the temporal rate of change in this distance through time. We used factorial analysis on mixed data to examine trait group responses to these predictors.RESULTS: Our results indicated that the occurrence of approximately half of the study region’s avifauna is strongly linked to the proximity of their habitat to the urban fringe, but that the impact of urban fringe development on the occurrence of some species changed through time. We identified several species of conservation concern that respond negatively to large annual increases in urban fringe development, irrespective of its proximity to suitable habitat. Species responses to urban proximity were linked to life history traits, with small,migratory, woodland-dependent species that rely on mid- and upper-canopy structures, clearly disadvantaged by urban environments.MAIN CONCLUSIONS: Our findings demonstrate the breadth of species responses to urban encroachment over much larger distances than is typically investigated in urban ecological studies. We identify guilds vulnerable to the impacts of urban fringe development and therefore in need of ecologically sensitive urban design. We argue that future urban expansion towards important fringe habitats will need to be planned strategically through space and time.This research received funding support from Conservation Planning and Research, Environment and Sustainable Devel-opment Directorate ACT Government and the Fenner Schoolof Environment and Society. DBL, PG and KI were sup-ported by the National Environmental Research Program. ADM was supported by an ARC Future Fellowship (FT100100358)
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